Behind President Barack Obama's toughened but modulated response to the Iranian election crisis is a calculation that when the dust settles, the United States will still face an unpredictable adversary that gets closer by the day to producing nuclear weapons. No one can say whether the unrest following disputed presidential elections will yield an Iran more willing to cut a deal over its disputed nuclear program, or less. But as Obama sees it, the United States must be ready to talk no matter who sits on the other side of the table. “My position coming into this office has been that the United States has core national security interests in making sure that Iran doesn't possess a nuclear weapon and it stops exporting terrorism outside of its borders,” Obama told reporters Tuesday. The new president has tried not to poison chances for negotiations over those threats, although that gave Republican critics room to call him timid. His unspoken strategy aimed at defusing Iran's nuclear threat has been coupled with public messages that seek to avoid giving Iran's rulers any ammunition to claim that the United States is meddling. “My role has been to say the United States is not going to be a foil for the Iranian government to try to blame what's happening on the streets of Tehran on the CIA or on the White House,” Obama said during a news conference, “that this is an issue that is led by and given voice to the frustrations of the Iranian people.” Days of deadly tumult and then quiet defiance on Tehran's streets mark the greatest challenge to Iran's ruling structure since the 1979 revolution. They also present a huge wild card for the new US administration that came to office pledging a fresh start with Iran after three decades of mutual suspicion and hostility. The budding outreach to Iran could be smothered in the cradle, as Obama acknowledged. “We have provided a path whereby Iran can reach out,” he said. “It is up to them to make a decision.” That's the same thing Obama said before the disputed June 12 election, and it's also the same thing President George W. Bush said during his last two years in office. The stakes are higher for Obama, in no small part because Iran's nuclear machinery is still chugging toward the ability to produce nuclear weapons if the regime chooses to do so. Iran insists its nuclear program is peaceful, and President Mahmoud Ahmadinejad has used the program as a nationalist rallying cry. Ahmadinejad claimed a landslide re-election despite obvious questions about the size and distribution of his support, and the results were endorsed by Iran's senior cleric, supreme leader Ayatollah Ali Khamenei. Ahmadinejad's main challenger, Mir Hossein Mousavi, claims the vote was fixed, and the heavy-handed government response has given Iran's largely disorganized resistance a new organizing principle. The election results could mean greater internal pressure on Ahmadinejad to improve relations with the West and bargain over the nuclear program, as Obama hoped out loud on Tuesday. “The fact that they are now in the midst of an extraordinary debate taking place in Iran, you know, may end up coloring how they respond,” Obama said. Leaders of Britain, France and Germany were quicker than Obama to weigh in on the Iranian upheaval or, in the case of German Chancellor Angela Merkel, to call for a recount.